1. Field of the Invention
This invention relates to an apparatus for introducing gas under pressure into a container and more particularly an apparatus adapted to prevent the overinflation of the container.
2. Description of the Prior Art
A common way to inflate pneumatic containers such as, for example, a bicycle tire, a football or the like, is to take it to a service station and use the provided air pump. The air supplied by these pumps is generally pressurized to 150 psi, the pressure needed to drive the pneumatic tools used at the station. However, this pressure is far in excess of that needed for most containers, particularly bicycle tires, with a maximum desired pressure of between 70 psi to 90 psi. Most gas stations will have a pressure regulator which can be adjusted to provide a limited pressure below the maximum of 150 psi. However, these regulators are often inaccurate and expensive to repair so that pressure in excess of that desired can be delivered, resulting in the overinflation and even rupture of the tire. Also, when tires of small volume are inflated, the possibility of their rupturing is enhanced due to the relatively short time required to inflate such a tire.
Many devices have been employed in an attempt to prevent excess pressure from accumulating in the container to be inflated. One such device used to limit container pressure is shown in Webb, U.S. Pat. No 3,450,147. The device allows pressurized air to be introduced into the container and includes an aperture closed by a spring-biased seal. The seal is unseated from the aperture so as to release air pressure only when the pressure in the container becomes greater than the spring pressure holding the spring seal against the aperture.
Thus, excess air is removed only after it has been introduced into the inflatable container and the pressure therein has reached or gone beyond the predetermined pressure. And since there exists the possibility of jamming or malfunctioning of the complex device, so as not to release excess pressure, the danger still exists that the container can rupture upon being filled. Further, failure of the seal due to wear and deterioration can result in loss of the ability of the device and inflatable container to retain the proper pressure.
Additional disclosures of valves used to inflate objects can be found in U.S. Pat. Nos. 1,551,710; 1,156,328; 1,004,986; 1,738,621; and 2,954,796.
As many bicycle tires, footballs, basketballs, and other inflatable objects are ruptured every day due to being filled with excess pressure, a need exists for a valve device which does not malfunction and which is easily operated so as to inflate the containers to the proper pressure.